Allergens are substances which trigger hypersensitivity reactions via the immune system. Statistics show that the number of people affected by such hypersensitivity reactions, triggered by allergens, is rising year by year. A large number of allergens, for example pollen, are transported by air, which is a problem particularly for asthmatics who react particularly sensitively to these allergens. Moreover, the number of asthmatics is increasing annually, which also exacerbates the situation.
Thus, there is a rising demand for filter materials which can remove the allergens from the air and can preferably also neutralize them.
In practice, polyphenols are often considered for reducing the allergy-triggering potential of the substances deposited on filter media, particularly tree pollen or house dust mite excrement. Thus, EP2879776 (A1) discloses the use of an allergen deactivator, comprising inter alia polyphenols from the family of tannins, in particular organic tannic acids in a filter medium. However, a disadvantage of polyphenols is that they have a relatively low anti-allergic potential, for example on filters, over a relatively long period of time: polyphenols as secondary plant substances mainly have a hydrophilic character and can therefore be degraded or washed out by ageing processes (large fluctuations in temperature and humidity) over the period of use of the filter.
US 2013/0183879 A1 describes the use of an allergen deactivator, comprising an aromatic sulphonic acid derivative in a filter medium. Organic acids are mentioned as auxiliaries. Aromatic sulphonic acid derivatives generally have an antibacterial action. However, a disadvantage of these substances is that resistances can develop.